Winged injection needle devices for use in epidural anesthesia and the like are known (see Patent Literature 1, for example). Such winged injection needle devices have a construction comprising an injection needle, a base member which supports the base end of the injection needle, and wings which protrude from the base member toward the left and right sides, the left and right wings functioning as a handle during use, allowing piercing to be accomplished in a stable manner.
Incidentally, when a used injection needle device is discarded as is, there is a risk that the needle tip may pierce the human body while being treated as waste, resulting in problems such as infection. Therefore, after use, it is encouraged to dispose of an injection needle device after covering it with a sheath-like safety cover (cap). However, with injection needle devices used for epidural anesthesia and the like, which have longer lengths for their injection needles compared to ordinary injection needle devices, there is a risk of inadvertent piercing of a finger by the injection needle when a medical attendant (doctor, nurse, etc.) covers the leading edge of the injection needle with a sheath-like safety cover.
To deal with this problem, there have been proposed safety covers composed of a tube-like body (nested or bellows-like type) that is freely expandable in the lengthwise direction of the injection needle, with a cover formed at one end thereof, and the other end being mounted on the base member of the injection needle device (see Patent Literature 2, for example). Such safety covers allow the injection needle to be covered by a maneuver of stretching from the base side of the injection needle, thus eliminating the problem of inadvertently piercing the finger with the injection needle when covering the injection needle.